Mitsubishi Electronics FX3G User Manual

FX

3S

/FX

3G

/FX

3GC

/FX

3U

/FX

3UC

 Series

Programming Manual - Basic & Applied Instruction Edition

4 Devices in Detail

Inputs X000 to X007 are assigned as shown in the table below according to each high-speed counter number.
When a high-speed counter is used, the filter constant of a corresponding input number in the main unit automatically
changes (X000 to X005: 5 

µs, X006 and X007: 50 µs). Input terminals not used for high-speed counters, however, can

be used as general inputs.
When FX

3U

-4HSX-ADP unit is connected to an FX

3U

 PLC, input terminals inside bold-line frames in the table below

are assigned to the first FX

3U

-4HSX-ADP unit, and other input terminals are assigned to the second FX

3U

-4HSX-ADP

unit.

→ For the input specifications of the FX

→ For the input specifications of the main unit, refer to the Hardware Edition of the main unit.

H/W: Hardware counter

S/W: Software counter

U: Up-counting input

D: Down-counting input

A: A phase input

B: B phase input

R: External reset input

S: External start input

*1.

Cautions on wiring should be considered for these high-speed counters.

→ For the wiring, refer to the Hardware Edition of the main unit.

*2.

Hardware counters are switched to software counters when a comparison set/reset instruction for high-speed
counter (DHSCS, DHSCR, DHSZ or DHSCT) is used.
The counter C253 is switched to a software counter when the logic of the external reset input signal is
reversed.

→ For the condition under which it is handled as a software counter, refer to Subsection 4.8.9.

*3.

When a special auxiliary relay is driven in a program, the input terminals and their associated functions are
switched.

→ For the method to use a software counter as a hardware counter, refer to Subsection 4.8.7.

*4.

In a 2-phase 2-count input counter, the edge count is usually 1. But the edge count can be set to 4 by
combining a special auxiliary relay.

→ For the method on how to use a 2-phase 2-count input counter with on edge count of 4,

1-phase

1-count 

input

C235

*1

H/W

*2

C236

*1

H/W

*2

C237

*1

H/W

*2

C238

*1

H/W

*2

C239

*1

H/W

*2

C240

*1

H/W

*2

C241

S/W

C242

S/W

C243

S/W

C244

S/W

C244(OP)

*3

H/W

*2

C245

S/W

C245(OP)

*3

H/W

*2

1-phase

2-count 

input

C246

*1

H/W

*2

C247

S/W

C248

S/W

C248(OP)

*1*3

H/W

*2

C249

S/W

C250

S/W

2-phase

2-count 

input*

4

C251

*1

H/W

*2

C252

S/W

C253

*1

H/W

*2

C253(OP)

*3

S/W

C254

S/W

C255

S/W